To solve this question, let's break down the reaction and understand the components involved:
[tex]\[
2 \, \text{HCl} \, ( \text{aq} ) + \, \text{Ca} ( \text{OH} )_2 ( \text{aq} ) \rightarrow 2 \, \text{H}_2\text{O} \, ( \text{l} ) + \, \text{CaCl}_2 ( \text{aq} )
\][/tex]
### Step-by-Step Solution:
1. Identify the components on both sides of the equation:
- On the reactant side, we have 2 molecules of hydrochloric acid (HCl) in aqueous form and 1 molecule of calcium hydroxide (Ca(OH)_2) in aqueous form.
- On the product side, we have 2 molecules of water (H_2O) in liquid form and 1 molecule of calcium chloride (CaCl_2) in aqueous form.
2. Determine the stoichiometric coefficient for water (H_2O):
- The equation shows that the production of water (H_2O) has a coefficient of 2. This means 2 moles (or molecules) of H_2O are formed in the reaction.
3. Interpret each option given:
- Option 1: 2 L H_2O
- This describes a volume (in liters) of water, which is not directly related to the number of moles or molecules specified in the reaction.
- Option 2: 4 moles H_2
- This specifies moles of hydrogen gas (H_2), which is irrelevant since hydrogen gas is not a product of this reaction.
- Option 3: 2 molecules H_2O
- This correctly matches the stoichiometric coefficient of water in the given balanced equation.
- Option 4: 1 molecule H_2O
- This depicts only one molecule of water, which is incorrect as per the balanced equation that shows two molecules of water are formed.
Given the analysis above, the correct option that describes the [tex]\( H_2 O \)[/tex] component in the reaction is:
2 molecules [tex]\( H_2 O \)[/tex]
